Screening and Management Considerations for the Geriatric Dog ...

test. If Cushing’s disease is suspected, it may be confirmed with a low dose dexamethasone
suppression test or ACTH stimulation test. Other diagnostic testing should include an abdominal
ultrasound, urine culture, and blood pressure determination.
Hypercalcemia
Hypercalcemia in dogs is most often associated with chronic kidney disease and
lymphosarcoma, although many other causes are certainly possible. Mild elevations in serum
calcium, in the absence of any other clinical findings should be monitored. Moderate to
significant increases in serum calcium should be evaluated rapidly to prevent the adverse
metabolic consequences; most notably, kidney damage. Parathyroid hormone and parathyroid
hormone-like assays that include the measurement of ionized calcium are helpful in the
differential diagnosis of hypercalcemia.
Hypergammaglobulinemia
Hypergammaglobulinemia is a relatively common biochemical abnormality, especially in cats.
Most often, mild hyperglobulinemia is associated with significant dental disease. Marked
hyperglobulinemia should prompt further investigation. Any chronic inflammatory or neoplastic
disease can result in elevated gammaglobulins via immune stimulation (eg inflammatory liver
disease). Serum protein electrophoresis is useful in determining if monoclonal or polyclonal
gammopathy is present. Radiographs will help to rule out multiple myeloma.
Anemia
Mild anemia is a common clinical finding in older pets. Anemia of chronic disease, chronic
kidney disease and many neoplasias are associated with a normocytic, normochromic, nonregenerative
anemia. Regenerative anemia is usually the result of blood loss. Patients with nonregenerative
anemia should be screened for intestinal parasites. Clinical history may provide an
indication of gastrointestinal blood loss (ie. melena). Immune mediated destruction of red blood
cells will also result in a regenerative anemia, but this is usually associated with cancer in older
pets. Hemangiosarcoma is an example of neo-plastic-induced blood loss anemia. Bone marrow
examination is especially important in determining the cause of nonregenerative anemias.
Thrombocytopenia
Potential etiologies of thrombocytopenia include immune-mediated destruction, disseminated
intravascular coagulation, platelet sequestration, and decreased bone marrow production.
Neoplastic diseases may result in thrombocytopenia via one or a combination of these disease
mechanisms. Measurement of platelet factor 3 assists in the diagnosis of immune-mediated
thrombocytopenia.
There are many other abnormalities, but time and space preclude their discussion here.
Treating the senior patient
Once a disease has been diagnosed, it is important to re member that age-related changes in
physiology may alter the pharmcokinetics of many drugs. Most drugs are metabolized via the
liver or kidney. Liver disease, hypoalbuminemia (albumin binds many drugs), CKD, and chronic
dehydration occur frequently in older patients and impact drug metabolism. When treating
geriatric patients, the dose and/or dosing intervals of some drugs may therefore need to be
altered.
While veterinary medicine can often offer sophisticated therapeutic options, it is important to
remember that older patients are often poorly tolerant of the stress involved with hospitalization